An antenna device having a plurality of antenna elements (radiating elements) is provided with signal lines that distribute input signals to each of the antenna elements. Such signal lines are formed by coaxial cables or microstrip lines and the like (Japanese Patent Application Laid-Open Publication No. 2002-368507: Patent Document 1). Sometimes different signal lines have to be intersected with each other depending on the wiring layout. When, for example, the signal lines are formed by microstrip lines, two wiring patterns may need to cross each other three-dimensionally on one side of the substrate.